Congo‘s attorney general Flory Numbi has said that he had opened an investigation into former minister Clement Kanku over allegations he played a role in the militia violence in central Congo that a U.N. employee was investigating when she was killed.

His announcement followed a report by The New York Times on Saturday (May 20) that Zaida Catalan, a U.N. investigator killed in March in central Democratic Republic of Congo, had a recording of a phone call between ex-development minister Clement Kanku and a presumed militia member.

In it, the newspaper reported, Kanku is heard speaking approvingly of violence perpetrated by the Kamuina Nsapu militia, whose insurrection against government forces in the Kasai region has resulted in hundreds of deaths and displaced more than a million people since last July 2016.

Kanku rejected all the allegations in a later news conference.

Attorney General Flory Numbi announced the government investigation to reporters in the capital Kinshasa, saying he had written to the National Assembly to request permission to conduct preliminary searches of Kanku’s property because he enjoys immunity as a member of parliament.